1. Field of Invention
The present invention relates to a liquid crystal display. More particularly, the present invention relates to a liquid crystal display containing sub-pixel electrodes.
2. Description of Related Art
Very wide viewing angles and high definition, among others, are the advantages of a multi-domain vertical alignment (MVA) liquid crystal display (LCD). Some slits and protrusions are formed on the inner surfaces of two transparent substrates in a conventional MVA LCD in which vertically aligned liquid crystal molecules are tilted symmetrically in opposite directions to compensate for viewing angles.
As disclosed in U.S. Pat. No. 6,922,183 (hereinafter, the “'183 patent”), the lateral electric field applied to the slits on the inner surface of the transparent electrode of an MVA LCD has to be increased, so the liquid crystal molecules in the proximity of the slit can be inclined efficiently and liquid crystal molecular response time can be reduced. A pixel electrode is divided into two sub-pixel electrodes, and thus a pixel is divided into two sub-pixels. The two equipotential sub-pixel electrodes with opposite polarities are electrically isolated to each other by the slit. Lateral electric field is created on the slits to reduce response time of liquid crystal molecules.
However, the invention disclosed by the '183 patent requires each of two sub-pixel electrodes to be connected with a switch as a driving device for the corresponding sub-pixel. The number of driving devices for each pixel is thus doubled. In addition, sub-pixels with opposite polarities must have their own contact holes to conduct their own electronic signals. When a pixel electrode is divided into several sub-pixel electrodes, sub-pixel electrodes with the same polarity have to be connected by additional wire in order to use one single switch as the driving device. The additional wire will increase both the complexity of electric circuit and the difficulty of manufacturing process.